From: mark@nin.com (Mark Beeson)
Newsgroups: alt.2600,alt.security.pgp,alt.religion.kibology
Subject: PGP/IDEA -Cracked!-
Date: 1 Apr 1995 08:36:03 GMT
Organization: [ Neural InterNetworking ]
Message-ID: <3lj39j$4c8@baygull.rtd.com>

--NOTE FROM SENDER (Mark)--

This may be a coverup.  IDEA/PGP makers may completely deny this.  But it's
true.  PGP and IDEA encryption can be cracked using a very simple algorithm.
This is a press release I stumbled upon on a site that shall be unnamed
(for security reasons -- if I divulged it I could be arrested).  Read on.

--END NOTE, BEGIN INCLUDED MESSAGE--

From : << DELETED FOR SECURITY REASONS >>
To   : << DELETED FOR SECURITY REASONS >>
Date : Sat Apr  1 00:05:07 EST 1995
Subj : PGP ENCRYPTION INSECURE -- CRACK IDEA USING SIMPLE ALGORITHM.


Gentlemen,

It has come to my knowledge that PGP/IDEA can be cracked, and easily.
This alarming data should not, at all costs, be released to the public,
and should only be forwarded to << DELETED FOR SECURITY REASONS >>.

The concept behind breaking the encryption is simple.  The security hole
that was found is this: The originating person's private keyphrase can be 
found _inside_ the actual PGP message.

Yes, that is alarming, isn't it?  The algorithm to pick out the private
keyphrase is even more alarming, and very simple.  Here's the base
equation:

( HEX VALUE OF FIRST CHARACTERS / NUMBER OF CHARACTERS ) ^ X

where X increases by one for every character found in the private keyphrase.

Instructions for using this equation:

- Translate all the characters in the first row of the encrypted message 
  to hexadecimal values, and take the sum total of those.
- Count the number of characters in the encrypted message and divide the
  sum total of the hex values by this number.
- Letters of the private keyphrase can be found at (ThisTotal) ^ X, where
  X increases after finding each letter.  Therefore the first letter can
  be found at (ThisTotal) ^ 1, or (ThisTotal).  The second letter can be
  found at (ThisTotal) ^ 2, and so on.

As an example, take this message.  You will find that you can easily
decrypt it using this algorithm.

-----BEGIN PGP MESSAGE-----
Version: 2.6.2

owFtkMFOg0AQhuvBCwnv8MulmgiEprGU1CogVI1tGhMfYC2DSwq7m2Ur8aV8RqHV
m9/tn5l8M5nv0ejs2Zwzpat61PPIlPpCPETkUtbj9sK2bMt1bQtYM71HQtRKgct1
EszCK/zHVlNbFSTMNTZ0APriL/Fo0L5!qfeV+Bhkx8HVFmWfSfcLhYkwnSDNEcwx
iRHMkKcIp4hDIH5AeIMgRpgNpWSOIEOa/ImOONknCaxkgU6KscGOs14NwwmKtcZz
ANdFKg+6JcgSWaMqTSfF2+tLhAUD11TeOtwYFfl+13WeNoW3k43PzXsl/NOxd03/
iPvfjrPkpGnhs6VnWz8=
=vp3z
-----END PGP MESSAGE-----

The exercise is left to the reader.

More details will follow as data is researched.  Currently the team of
<< DELETED FOR SECURITY REASONS >> is working on a version of this for
binary files.  It is assumed that there should be no difference between
binaries and ASCII-armored text, only that the binary files need to be
accessed by a simple C program that will read binary data instead of
ASCII data.

Yes, gentlemen, this is alarming, but if the general public does not
get ahold of this information, perhaps we can use this to our
advantage.  I'm sure you remember Clipper -- maybe if these new PGP/
IDEA developments are kept confidential, we will be able to read the
public's encrypted data after all.

Cordially,

<<DELETED FOR SECURITY REASONS >>
E-Mail: << DELETED FOR SECURITY REASONS >>


--END INCLUDED MESSAGE--


I can only assume that PGP and IDEA are insecure, folks.  *sigh*  This
is pretty depressing news.

--Mark
mark@nin.com
--
  Mark Beeson (MB178)                     President, Neural InterNetworking
      PGP fingerprint: 42 CF 19 2A 17 FC 84 A8  AD 86 1A 8E 84 B9 1E CB
           "Even God won't change the past."  -- Course of Empire
    URL: here.

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